The CPWC varied between years (Fig. 2). Based on the 5%
acceptable yield loss (AYL), the beginning of the CPWC in field corn was 175 GDD in 2013 and 165 GDD in 2014, suggesting the initiation of weed control at 20e21 DAE (Table 5). The beginning of the CPWC in popcorn was 92 GDD in 2013 and 110 GDD in 2014, which corresponded to 12e14 DAE. In sweet corn, the beginning of the CPWC in 2013 was 203 GDD and in 2014 was 182 GDD, indicating the beginning of weed removal at 22e23 DAE